The January thaw in New England has even reached New Hampshire's Mount Washington, which recorded its all-time warmest temperature ever for the month.

Margaret Curtis from the National Weather Service in Gray, Maine, said the temperature at the Mount Washington Observatory hit 48 degrees at 6 a.m. Sunday, making New England's tallest mountain warmer than Phoenix and San Diego for a brief spell.

The previous record warmth for the month atop Mount Washington was 47, set on Jan. 20, 1995.

Curtis said temperatures will begin cooling across the region to more seasonable temperatures starting Monday, with the possibility of a shot of extreme cold Friday into Saturday.